This invention relates to bushings, and in particular, to a drill bushing for guiding a drill bit reamer or tap in a production operation.
In order to maintain accuracy in a production operation, a replaceable drill bushing is used to guide a drill bit, reamer or tap. The drill bushing may be slip fit into a liner which is press fit into a mounting hole in a jig plate or fixture, or may be slip fit directly into a mounting hole in a jig plate or fixture. A locking screw or a clamp block is used to maintain the bushing in the liner or in the mounting hole. Because of the large number of types of drill bits, reamers and taps utilized in production operations, and the many different environments in which a drill bushing is used, there are a large number of types and sizes of drill bushings. This, in turn, increases the inventory requirements for the end users of the drill bushings, and increases the number of drill bushings a manufacturer must produce for customers. As a result, it is highly desirable to develop a drill bushing which may be used in many environments, so as to reduce the number of different types of bushings.
Therefore, it is a primary object and feature of the present invention to provide a drill bushing which accurately guides a tool in a production operation.
It is a further object and feature of the present invention to provide a drill bushing which may be used in different environments.
It is a still further object and feature of the present invention to provide a drill bushing which may be secured in a liner or a mounting hole in a jig plate in numerous different manners.
A drill bushing is provided for centering the point of a tool in a production operation. The drill bushing includes a generally cylindrical body extending along the longitudinal axis. The cylindrical body has first and second ends, and the central passage for guiding the tool bit.
A head, integral with the first end of the cylindrical body and having an enlarged diameter, is provided. The head includes first and second sides perpendicular to the longitudinal axis. A first concave recess on the periphery of the head extends from the first side of the head toward the second side of the head to form a first shoulder. A second liner recess on the periphery of the head, spaced from the first recess, extends from the first side of the head towards the second side of the head to form a second shoulder. The second shoulder includes a third concave recess on the periphery of the head extending through the second shoulder.